Sources of benzophenanthridine alkaloids include five plant families: Papaveraceae, Fumariaceae, Rutaceae, Capifoliaceace, and Meliaceae. Two of the most important sources of benzophenanthridine alkaloids are found in the Papaveraceae family. These plant species are Sanguinaria canadensis L. (bloodroot) and Macleaya spp. Sanguinaria canadensis L. is commonly known as bloodroot puccoon, teterwort and is a perennial plant native to North America. The plant and its extracts have been used as a folk remedy for treating asthma, bronchitis, dysentery, ringworm and other ailments. The rhizome of the plant has been used as an expectorant in cough syrups and in homeopathic medicine.
Recently Sanguinaria extract derived from the rhizome has been used as an antiplaque and gingivitis agent as shown in U.S. Pat. No. 4,145,412 with zinc chloride, and as an antimicrobial agent in U.S. Pat. No. 4,406,881 and USSR Patent No. 230,387. The following patents describe the use of benzophenanthridine alkaloid extracts in medical ailments: U.S. Pat. No. 4,376,115; U.K. Patent No. 2,042,336; German Patent No. 2,907,406; and Belgian Patent No. 888,843.
As a result of their activity in treating medical conditions it has become increasingly important to develop methods for extraction of these benzophenanthridine alkaloids from plant biomass. It has also become important to develop commercial methods for purifying and separating these benzophenanthridine alkaloids from each other. The benzophenanthridine alkaloids of interest are sanguinarine, chelerythrine, sanguilutine, chelilutine, chelirubine and sanguirubine. In the past, methods for the separation of these alkaloids from each other included column chromatography and thin layer chromatography. However, these methods do not lend themselves to production of commercial quantities of these alkaloids.
The prior art for extracting the benzophenanthridine alkaloids from plant biomass include the extraction of cut or ground bloodroot with methanol at elevated temperatures, filtering the liquid extract, evaporating the extract to dryness, dissolving the dried extract in chloroform, adjusting the pH of the chloroform solution with acid such as hydrochloric acid, collecting the filtered extract, and drying of the extract. This procedure is disclosed in U.S. Pat. No. 4, 145,412, incorporated herein by reference. Other patents for the extraction of benzophenanthridine alkaloids from plant biomass include USSR Patent No. 495,331 for extracting Chelidonium majus from benzophenanthridine alkaloids.
German Patent No. 2,856,577 discloses a method of benzophenanthridine alkaloid extraction by treating chopped plant materials with an ammonia solution and subsequent extraction with trichloromethane solution. Sulfuric acid is added and the solvent is distilled off. The residue is basified with ammonia to precipitate the alkaloid free bases. The bases are collected.
U.S. Pat. No. 4,818,533 describes the extract of plant material for benzophenanthridine alkaloids using a pH 8.5 solution of water and co-solvent such as methylene chloride to dissolve the alkaloid. The methylene chloride solution is washed with acidified water and the benzophenanthridine alkaloids are precipitated as the acid salt.
Other U.S. patents describing the extraction of benzophenanthridine alkaloids from a plant biomass include: 4,767,861 and 4,769,452.